38t» .MLsUZOlC FLORAS OF LMTKD SIATE.S. 



was excavated chiefly in a heav}^ bed of Rappahannock sand in which 

 much siHcified wootl occurs. Several of the specimens treated by Doctor 

 Knowhon were obtained from this locahty, and one immense lofj; was 

 uncovered on the west side near tlie shaft, which has never l)een taken 

 out and is now waUed in. M tliis date the bottom of tlie reservoir was 

 mostly dry, excejit U)v the stream from what was called the Capitol 

 Spring, which coui'sed through it. Below tiiis Ijed of sand is one of 

 lignite, and this could then l)e traced all the way round the reservoir. 

 It was seen to thicken somewhat on the west side. About midway of 

 the reserA'oir from north to south, but on the east side, a little north of 

 opposite the shaft and as mncli south of opposite the Capitol Spring 

 tower, therefore only a short distance from the extreme southwest corner 

 of the Soldier's Home inclosure, a few feet above the lignite bed, I foimd 

 in a stratum of sandy clay quite abundant remains of plants, chiefly 

 ferns, and, as it proved, nearly all belonging to one specifies (see p. 

 516). The vegetable matter was black, but tended to peel oft'. 



Crossing to the west side, near the shaft I found another plant- 

 bearing vein consisting of buff-colored clay \\i1h sand partings, and 

 A'ery frail. It held remains of conifers, cycads, and Gingkoacea? (see 

 p. 516). 



About two weeks later, on October 2, 1892, I took Doctor Arthur 

 Hollick to this locahty and we made a small collection near the spot first 

 described, Ijut we must have worked in a different vein, for nearly all 

 the specimens consisted of tubers of Equisetum. 



In October, 1892, I spent six days in reexamining the Potomac beds 

 on the James and Appomattox rivers. I was specially interested to see 

 if any basal clays could be found, as all the plants collected l3>- Professor 

 Fontaine had come from clay lenses in the coarse sands. That these 

 lenses must have been parts of an imderlying clay stratum was self-evident, 

 but the latter seemed to have been entu-ely eroded away before the depo- 

 sition of the sands, and only a few remnants left in the form of lenses, the 

 sand underlying as well as overlying them. These clay lenses become 

 numerous in descending the James after passing Wai-wicks Park, some 

 7 or 8 miles below Richmond. At Drurys Bluff they are prolonged into 

 strata varjdng in color, but clearly- included in the coarse sands. They 

 here rise 15 or 20 feet. Below Kingsland, Proctor Creek, and Red Water 



